The light‐harvesting core‐complex and the B820‐subunit from Rhodopseudomonas marina. Part I. Purification and characterisation

FEBS Letters

Zuber, Herbert¹  Meckenstock, Rainer U.¹  Brunisholz, René A.¹ 

[1] Institut für Molekularbiologie und Biophysik, ETH-Hönggerberg, CH-8093 Zürich, Switzerland

关键词: Rhodospirillaceae;    Light-harvesting complex;    Non-sulfur purple bacteria;    Bacteriochlorophyll α;    B880;    B820;    B880;    core-antenna complex with an absorption maximum at 880 nm;    B820;    subcomplex with an absorption maximum at 820 nm;    B873;    core-antenna without carotenoids and an absorption maximum at 873 nm;    B860;    core-complex which was reassociated from B820 and has its absorption maximum at 860 nm;    RC;    reaction center;    CD;    circular dichroism;    NIR;    near infra-red;    OG;    n-octyl-β-glucoside;    LDAO;    lauryl-N;    N-dimethyl-amine-N-oxide;    LDS;    lithium dodecyl sulfate;    Tris;    tris[hydroxymethyl]aminomethane;    BChl;    bacteriochlorophyll;    Rp;    Rhodopseudomonas;    kDa;    kiloDalton;    PAGE;    polyacrylamide gel electrophoresis;   

DOI  :  10.1016/0014-5793(92)81383-W

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The BChla-containing B880-complex (core-complex) of Rhodopseudomonas marina (Rhodospirillaceae) was isolated with a new purification method. The isolation of the B880-complex was performed by solubilisation of the photosynthetic membranes with the detergent LDAO and subsequent fractionated ammonium-sulfate precipitation with about 50% recovery. The B880-complex retained its original spectral properties as revealed with absorption, fluorescence and circular dichroism spectroscopy. Furthermore, we dissociated the B880-complex with the detergent n-octyl-β-glucoside (OG) and purified the developed subcomplex by the method of Miller et al. [1], which showed an absorption maximum at 820 nm (B820). The α- to β-polypeptide ratio and the α- or β-polypeptide to BChla ratio, respectively, were estimated to be 1:1 in both complexes. The molecular weights of the B880 and the B820-complexes, determined by gel filtration chromatography, were 181 and 32 kDa, respectively. Thus, it appears that the B880-complex of RP. marina consists of 24 polypeptides and the B820-complex of four polypeptides. Six B820-complexes or possible subunits could form the B880-complex. On the basis of these data we propose a model for the structure or BChla containing core-complexes.

【 授权许可】

Unknown